In the related art, as a vehicular heads-up display device of this type, for example, the one disclosed in Patent Literature 1 shown below is known. The vehicular heads-up display device described in Patent Literature 1 is mounted inside an instrument panel (hereinafter, referred to as “INP”) of the vehicle, and includes a liquid crystal display configured to issue travelling information relating to travel of the vehicle as display light, a light source (a light-emitting body) composed of an LED disposed adjacent to the liquid crystal display, a circuit board on which a wiring pattern for mounting the light source is formed, a reflection mirror configured to reflect the display light emitted by the liquid crystal display and outgoing light (illumination light) emitted from the light source, and a unit case (case body) configured to house the liquid crystal display, the light source, the circuit board, and the reflection mirror, and an opening to allow the display light and the outgoing light described above reflected by the reflection mirror to pass therethrough is formed on the upper end side of the unit case so as to open.
Then, the vehicular heads-up display device configured as described above is configured to cause the display light from the liquid crystal display reflected by the reflection mirror and the outgoing light from the light source to go out to the outside of the unit case via the opening provided in the unit case, and to reflect on a windshield of the vehicle as a reflecting member toward a driver, and allows a user of the vehicle as a driver to visually identify a virtual image obtained by this reflection.
In this case, the vehicular heads-up display device includes control means including a microcomputer configured to cause the liquid crystal display to perform a display operation and cause the light source to perform a lighting operation mounted on the circuit board, and such control means causes the liquid crystal display to perform the display operation to display also a signage “CHECK” in addition to the traveling information (vehicle speed display) on the liquid crystal display and, simultaneously, causes the light source to perform the lighting operation to display a circular alarm sign, described later, as part of the virtual image upon reception of a state signal indicating that only a small amount of fuel remains for example.
Then, the light source is illuminated simultaneous with the emission of vehicle speed display light and signage display light such as “CHECK” from the liquid crystal display, and the vehicle sped display light, the signage display light, and the outgoing light emitted from the light source are reflected toward the driver through a reflection mirror, the opening of the unit case, and the windshield, whereby the driver is capable of observing the virtual image composed of the vehicle speed display, the signage display such as “CHECK”, and the circular alarm sign with a landscape superimposed thereon. The alarm sign displayed as part of the virtual image is displayed for letting the driver to reliably notify the fact that the signage display such as “CHECK” is displayed.